Re: c/10339: strncmp generates imPure code

[Michael Ubell <ubell at mindspring dot com>]

The following reply was made to PR optimization/10339; it has been noted by GNATS.

From: Michael Ubell <ubell at mindspring dot com>
To: Andreas Schwab <schwab at suse dot de>
Cc: Timothy C Prince <tprince at myrealbox dot com>, 
 falk dot hueffner at student dot uni-tuebingen dot de,  bangerth at ices dot utexas dot edu, 
 gcc-bugs at gcc dot gnu dot org,  gcc-gnats at gcc dot gnu dot org
Subject: Re: c/10339: strncmp generates imPure code
Date: Mon, 07 Apr 2003 14:28:29 -0700

 Andreas Schwab wrote:
 > Michael Ubell <ubell at mindspring dot com> writes:
 > 
 > |> Attached is a program that reads 831 unaligned unallocated
 > |> bytes.  I can't actually get it to segv on Solaris because
 > |> I don't know enough about their memory management, but
 > |> I cannot believe this is correct code.
 > 
 > Yes, you are right, I can reproduce that also on ia64-linux.  The
 > conversion to memcmp is really invalid here.
 > 
 > Andreas.
 > 
 
 Now I get to argue the other side :-)  Was your string properly null
 terminated?  If not, then its not the compiler's fault.  I think
 memcmp is valid so long as the strings are well formed.  This will
 be true because C strings may not contain embedded nulls.